Signed-off-by: Tzung-Bi Shih tzungbi@kernel.org --- PoC patch.
v4: - New in the series.
drivers/char/misc.c | 7 +++++++ include/linux/miscdevice.h | 3 +++ 2 files changed, 10 insertions(+)
diff --git a/drivers/char/misc.c b/drivers/char/misc.c index 726516fb0a3b..fcbbb0b1af35 100644 --- a/drivers/char/misc.c +++ b/drivers/char/misc.c @@ -159,6 +159,13 @@ static int misc_open(struct inode *inode, struct file *file)
err = 0; replace_fops(file, new_fops); + + if (c->rp && c->rops) { + err = revocable_replace_fops(file, c->rp, c->rops); + if (err) + goto fail; + } + if (file->f_op->open) err = file->f_op->open(inode, file); fail: diff --git a/include/linux/miscdevice.h b/include/linux/miscdevice.h index 7d0aa718499c..00f5c878266a 100644 --- a/include/linux/miscdevice.h +++ b/include/linux/miscdevice.h @@ -5,6 +5,7 @@ #include <linux/list.h> #include <linux/types.h> #include <linux/device.h> +#include <linux/revocable.h>
/* * These allocations are managed by device@lanana.org. If you need @@ -92,6 +93,8 @@ struct miscdevice { const struct attribute_group **groups; const char *nodename; umode_t mode; + struct revocable_provider *rp; + const struct revocable_operations *rops; };
extern int misc_register(struct miscdevice *misc);